For vehicles wherein a movable vehicle part generally referred to as a slider slidingly translates from one position to another relative to another vehicle part, a smooth sliding action is essential for user satisfaction. Any discontinuity or erratic movement between the slider and the other vehicle part contributes to user dissatisfaction, being interpreted as improper fit and/or finish.
Preliminarily, various terms are used herein to describe movement of vehicle parts relative to one another, such as movement of a slider on and/or in another vehicle part. As used herein, unless stated otherwise motion descriptors such as “vertical,” “up-down,” “upwardly,” “downwardly,” “lateral,” “laterally,” and “side to side” refer to movement of a slider relative to a path of travel of the slider on and/or in another vehicle part.
With reference to FIG. 1, as an example a B-pillar trim piece 100 is often provided with a hidden gap hider configured as a D-ring slider 110 for adjusting a seat belt height adjuster mechanism (not shown). The B-pillar trim piece 100 serves as a substrate against and within which the D-ring slider 110 slidingly translates upwardly and downwardly to adjust a height of the seat belt height adjuster mechanism to a user's personal preference.
To control this relative sliding motion, the B-pillar trim piece 100 is provided with various structures to constrain vertical and lateral movement of the D-ring slider 110, to ensure that the D-ring slider only moves in the desired directions. Typically this is done using various guide rib structures 120 (see inset) to constrain lateral movement of the D-ring slider 110 and various other guide structures (not visible in this view) to constrain vertical movement of the D-ring slider.
These guide rib structures 120 typically include a plurality of ribs 130 which are oriented in a substantially vertical orientation. That is, as shown in the drawing figure, relative to a path of travel T of the D-ring slider 110 the ribs 130 are oriented in a substantially vertical orientation which is substantially perpendicular to the D-ring slider 110's path of travel. Thus, the D-ring slider 110 contacts the ends of multiple ribs 130 of the guide rib structures 120 as it slidingly translates over/within the B-pillar trim piece 100.
Such guide rib structures 120, while serving to constrain lateral movement of the D-ring slider 110, are flawed because of the separation between the rib 130 ends, which are tactilely perceived as intermittent points of contact or “steps” between the D-ring slider and the B-pillar trim piece 100 along the D-ring slider path of travel T.
An ideal solution would be to provide a guide rib structure 120 that is integral to the B-pillar trim piece 100 and which maintains an uninterrupted sliding contact between the D-ring slider 110 and the B-pillar trim piece as the D-ring slider translates over its path of travel T. FIG. 2 illustrates such an exemplary “ideal” guide rib structure. In the drawing figure, a substrate 200 is shown including a guide structure 210 for constraining vertical movement of a slider 220 and a guide rib structure 230 for constraining lateral movement of the slider. The guide structure 210 comprises a plurality of ribs 240 which contact a surface of the slider 220 to constrain vertical movement. The guide rib structure 230 is defined by a single rib 250 which maintains a constant contact with an edge of the slider 220 to constrain lateral movement. The rib 250 is integral to the substrate 200, contacts the substrate at one or two points of contact 260a, 260b, and defines a hollow through-bore 270.
Unfortunately, particularly in the case of molded plastic parts which must be extracted from a mold, this solution is not feasible using conventional manufacturing processes employing conventional tooling. This is in part due to the relative size of the substrate 200, the relative fragility of the guide rib structure 230/rib 250 and the difficulty of extracting both from a same mold in a single action. In particular, it would be difficult or impossible without use of specialized molding/injection techniques to provide a mold that could concurrently define the substrate 200, the guide structure 210 and the integral rib 250 in a manner that the molded piece could be removed without damaging some portion of the structure. Use of specialized techniques such as gas-assisted injection would cause gas to fill an inner void space between the guide rib structure 230 and the rib 250, in which case the component geometry would not be a hollow through-bore but instead would be a closed shell.
Thus, a need is identified in the art for vehicle parts including guide rib structures for constraining lateral motion of a moving part such as a slider, which approach the ideal solution of a constant point of contact between the slider and the vehicle part but for which fabricating by conventional molding processes is feasible.